I have found it very difficult to find information on running the scheduler anywhere in the forums or the wiki.

The easiest way to invoke the scheduler in a web app is to include the following in the web.xml

 <!-- JbpmThreadsServlet -->
  <servlet>
    <servlet-name>JbpmThreadsServlet</servlet-name>
    <servlet-class>org.jbpm.web.JbpmThreadsServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>JbpmThreadsServlet</servlet-name>
    <url-pattern>/threads</url-pattern>
  </servlet-mapping>